One of the world’s largest four-cylinder two-stroke marine diesel test engines (the electronically-controlled 4UE-X3 with a bore diameter of 60 cm) has been installed and brought up to speed at MHI, Mitsubishi Heavy Industries’ Nagasaki Research & Development Centre, where it thumps away producing data the Japanese marine engine manufacture needs to keep up with the leaders in a highly competitive business.
MHI claims it is the only licensor among the top three in the world to carry out all of its own engine development, design and manufacturing.The company is focusing its R&D attention on the slow-speed diesel, the workhorse engine of choice for the majority of the 50,000 or so large merchant ships that continually ply the oceans in global trade. Engine of choice by shipowners, it normally burns heavy C bunker oil, the cheapest dregs of oil in the refining process, but nevertheless it is also energy efficient.
As a sole propulsion engine, it achieves thermal efficiency as high as about 50% with a directly coupled slow propeller shaft rotational speed of about 100 rpm.
The test engine is being used not only to verify the performance and reliability of the latest engine technologies, but also to develop engines capable of operating on different kinds of fuel (gaseous fuels, like LNG in particular) so as to comply with increasingly stringent engine exhaust gas emission regulations. For example, with this in mind, an EGR (Exhaust Gas Recycling) system, has been tested already and the NOx reduction effect ascertained.
MHI plans eventually to bring the 4UE-X3 engine to the market after its performance has been fully optimised.
Test Engine Features
Main body structure: The main body (bed plate and column) uses a high rigidity, light-weight and simple single wall structure for simplicity of manufacture. The structure and thickness of the wall is optimized through FEM analysis using 3D modeling, etc.
Combustion chambers: Bore cooled, high top land pistons are used to deal with the high heat load. The cylinder liners employ a new construction with reinforced rings.
Bearings: The main and crankpin bearings are aluminium bearings instead of conventional white metal bearings.
Electronic control: Full electronic control is employed, in line with the compact and reliable Eco system used on the latest commercial engines.
Lubricating system: The latest A-ECL system, which can reduce lubricating rate, is used as the cylinder lubricating system.
Test plant control: Remote control and alarm systems are installed in order to simulate actual operation on a ship. In addition, MHI's DIASYS Netmation® control system was used for the integrated control of auxiliary machines and ancillary facilities
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